[pvr] fix deviations of selected item between PVR windows and channel OSD

As discussed in our forum (http://forum.xbmc.org/showthread.php?tid=175135&pid=1795411#pid1795411) this fix the deviations of the selected item between the PVR windows and the channel osd.

I also changed the way the current playing channel is used for the selected item. It's only used if we never have valid selected item or if we switch the channel otherwise we use the stored selected item. Thanks Jönke for this suggestion.
[Cleanup] Remove not working stereo to mono split mode/setting.

Conflicts:
	xbmc/video/dialogs/GUIDialogAudioSubtitleSettings.cpp
[pvr] cosmetics: correct wrong code format
dvdplayer: fix flushing message queue
Merge pull request #5027 from ace20022/rem_stereo_to_mono

[Cleanup] Remove broken stereo to mono split mode/setting.
Merge pull request #5405 from xhaggi/pvr-fix-printf-format-mismatch

[pvr] fix wrong printf format mismatch
pvr: fix deadlock in TriggerEPGUpdate
Merge pull request #5406 from FernetMenta/msg

dvdplayer: fix flushing message queue
[pvr] fix backend info never gets updated when only one pvr client enabled
[pvr] add ability to show free/used disk space of backend
Merge pull request #5401 from xhaggi/pvr-fix-sync-selected-item

[pvr] fix deviations of selected item between PVR windows and channel OSD
[confluence] add pvr disk indicator in recordings view
Merge pull request #5303 from Glenn-1990/pvr_diskspace

[pvr] diskspace indicator in recordings view
dvdplayer: fix ass subs for AV_CODEC_ID_ASS after ffmpeg bump to 2.4
Merge pull request #5409 from FernetMenta/epg

pvr: fix deadlock in TriggerEPGUpdate
AE: only send resample ratio if it was changed
ActiveAE: better 2 duplicate loc than recursive locking and an addition function call, fix after d66354dccada58c5da5ff5d940cd0942b9264a64
Merge pull request #5413 from FernetMenta/ass

dvdplayer: fix ass subs for AV_CODEC_ID_ASS after ffmpeg bump to 2.4
Merge pull request #5417 from FernetMenta/aefixes

AE: optimization and fixes
Remove videoplayer.useframemtdec setting and make it default